Lp(a) is a lipoprotein that is similar to LDL. Like LDL, it contains an apo B molecule and a cholesterol rich lipid core. However, unlike LDL, Lp(a) has a unique sugar protein on its surface which makes it much more likely to cause blood clotting. On a standard cholesterol test, the estimated LDL contains both Lp(a) and other particles. These are not reported separately but rather as part of the total LDL cholesterol concentration. This renders risk assessment difficult, because Lp(a) responds to therapy differently than does LDL and confers a different cardiovascular risk.
Lipoprotein (a) [(Lp(a)] blood levels are mostly determined by inherited genes. Elevated levels of LP(a) are associated with an increased risk of coronary heart disease and the development of blood clots, including deep venous thrombosis and pulmonary embolus.
In a large prospective study1 of 9936 healthy men and women with no prior history of coronary heart disease (CHD), an elevated Lp(a) level was associated with an increased risk of developing CHD. The higher the Lp(a) level, the greater the risk of coronary heart disease.
There is a strong genetic influence on the levels of Lp(a), which are higher in African Americans than in Asian or Caucasian patients.
1 Nguyen TT, Ellefson RD, Hodge DO, et al. Predictive value of electrophoretically detected lipoprotein (a) for coronary heart disease and cerebrovascular disease in a community based cohort of 9936 men and women. Circulation. 1997;96: 1390–1397.